For purposes of this application, the present invention is discussed in reference to efficacy of appetite-affecting drugs, or agents, but the present invention is applicable to any drug for which the efficacy is sought.
Drug efficacy is a constant study conducted in numerous research fields. Particularly, with respect to drug efficacy on appetite, it is desirable to determine whether chronic administration of such drugs, or agents, can produce a sustained decrease in daily food intake.
It has long been known to administer appetite-affecting agents, such as putative anorexigenic or anti-obesity agents, to an animal and then observe the effects, if any, on the animal's feeding pattern, or eating habits. Known methods of administering appetite-affecting agents typically include either daily injections or insertion of an osmotic mini-pump beneath the skin or into the peritoneal cavity to deliver agents continuously for a week or more. In addition, the food provided to the animal is weighed on a regular basis so that daily food intake can be monitored. Typically, these methods are inconclusive due to an increase in food intake between administrations of the agent as well as a developed tolerance to the agent.
After the administration is complete, the animals are evaluated to determine what effect, if any, the appetite-affecting agent had on the animal's eating habits. Typically, such evaluation has been limited to analyzing the animal's daily food intake by weight and dissecting the animal to determine adiposity, which is the amount and type of fat stored in fatty tissue. Conclusions regarding the agent's overall efficacy are based primarily on this evaluation.
Methods for evaluating drug efficacy have problems. For example, animals can experience decreased appetite following administration of appetite-affecting agents, and thus an overall decrease in food intake for a duration of time. It is also known that animals may experience hyperphagia, or excessive hunger leading to an increased food intake. This typically occurs following an anorexic episode that follows a dose of an anti-obesity appetite-affecting agent. Similarly, an animal may develop a tolerance to the appetite-affecting agent if administered in a particular dose over too long a duration of time. Thus, evaluating the efficacy of an administered drug requires an ability to measure the instantaneous effects of different doses including frequency of administration of the drug on feeding patterns.
A specific example related to the above-described problem includes difficulty in adjusting administration of the agent with respect to dosage and frequency to balance hyperphagia against anorexic episodes. Because the data collected by current methods is limited, it is difficult to maximize the efficacy of agents to augment an animal's feeding patterns. Limited data hinders an accurate analysis of feeding patterns as well as the ability to track changes in these patterns. Increasing the number of animals observed cannot alleviate these problems, thus, these problems prevent sufficient data management, including collection and analysis, to optimize the efficacy of appetite-affecting agents.
A demand therefore exists for a system and methods to administer and evaluate drugs. Data is collected and analyzed to determine the effects that a particular agent has on appetite including, for example, identifying feeding patterns and the effect the agent has on those feeding patterns. The present invention satisfies the demand.